Micro-tubular proton-conducting solid oxide fuel cells (SOFCs) are developed with thin film BaZr0.1Ce0.7Y0.1O3-delta (BZCYYb) electrolytes supported on Ni-BZCYYb anodes. The substrates, NiO-BZCYYb hollow fibers, are prepared by an immersion induced phase inversion technique. The resulted fibers have a special asymmetrical structure consisting of a sponge-like layer and a finger-like porous layer, which is propitious to serving as the anode supports for micro-tubular SOFCs. The fibers are characterized in terms of porosity, mechanical strength, and electrical conductivity regarding their sintering temperatures. To make a single cell, a dense BZCYYb electrolyte membrane about 20 mu m thick is deposited on the hollow fiber by a suspension-coating process and porous Sm0.5Sr0.5CoO3 (SSC)-BZCYYb cathode is subsequently fabricated by a slurry coating technique. The micro-tubular proton-conducting SOFC generates a peak density of 254 mW cm(-2) at 650 degrees C when humidified hydrogen is used as the fuel and ambient air as the oxidant. (C) 2010 Elsevier B.V. All rights reserved.